Maximum material condition (MMC) is the condition when a component or feature of a component has the maximum amount of material.
For a shaft, MMC would be when the diameter is everywhere at its maximum size.
For a hole, MMC is when its diameter is everywhere at its minimum size.
| Definition | Abbreviation | Meaning |
|---|---|---|
| Maximum material condition | MMC | The state of a feature where the feature is everywhere at its maximum material |
| Maximum material size | MMS | The limit of size where the material of a feature is at its maximum. Shaft - maximum limit of size Hole - minimum limit of size |
| Maximum material virtual size | MMVS | The maximum material size plus or minus the geometrical tolerance. (for a shaft) MMVS=MMS + geometrical tolerance (for a hole) MMVS=MMS - geometrical tolerance |
| Maximum material requirement | MMR | When MMR is required on a drawing it is indicated on the drawing by placing the symbol |
The 
symbol can be placed in the tolerance frame in the following ways:
The maximum material principle applies only to features with an AXIS or MEDIAN PLANE.
The actual measured diameter of the pin (figure 12.1) depicts the total increase in straightness tolerance. If the actual pin is 20 the allowed straightness tolerance is 0.1 but if the actual pin is 19.96 then...
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